Intima-media thickness at the near or far wall of the common carotid artery in cardiovascular risk assessment.

Aims: Current guidelines recommend measuring carotid intima-media thickness (IMT) at the far wall of the common carotid artery (CCA). We aimed to precisely quantify associations of near vs. far wall CCA-IMT with the risk for atherosclerotic cardiovascular disease (CVD, defined as coronary heart disease or stroke) and their added predictive values. Methods and results: We analysed individual records of 41 941 participants from 16 prospective studies in the Proof-ATHERO consortium {mean age 61 years [standard deviation (SD) = 11]; 53% female; 16% prior CVD}. Mean baseline values of near and far wall CCA-IMT were 0.83 (SD = 0.28) and 0.82 (SD = 0.27) mm, differed by a mean of 0.02 mm (95% limits of agreement: -0.40 to 0.43), and were moderately correlated [r = 0.44; 95% confidence interval (CI): 0.39-0.49). Over a median follow-up of 9.3 years, we recorded 10 423 CVD events. We pooled study-specific hazard ratios for CVD using random-effects meta-analysis. Near and far wall CCA-IMT values were approximately linearly associated with CVD risk. The respective hazard ratios per SD higher value were 1.18 (95% CI: 1.14-1.22; I² = 30.7%) and 1.20 (1.18-1.23; I² = 5.3%) when adjusted for age, sex, and prior CVD and 1.09 (1.07-1.12; I² = 8.4%) and 1.14 (1.12-1.16; I²=1.3%) upon multivariable adjustment (all P < 0.001). Assessing CCA-IMT at both walls provided a greater C-index improvement than assessing CCA-IMT at one wall only [+0.0046 vs. +0.0023 for near (P < 0.001), +0.0037 for far wall (P = 0.006)]. Conclusions: The associations of near and far wall CCA-IMT with incident CVD were positive, approximately linear, and similarly strong. Improvement in risk discrimination was highest when CCA-IMT was measured at both walls.

Can ambulatory blood pressure measurements substitute assessment of subclinical cardiovascular damage?

OBJECTIVE: We have previously demonstrated that markers of subclinical organ damage (SOD) improve cardiovascular risk prediction in healthy individuals. We wanted to investigate whether this additive effect of SOD was due to inaccurate blood pressure (BP) measurement or whether ambulatory BP (AMBP) added further to risk prediction. METHODS: In a population cohort of 1385 Danish individuals free of cardiovascular disease and diabetes, we recorded traditional risk factors, AMBP and pulse wave velocity (PWV), urine albumin/creatinine ratio (UACR), left ventricular mass index (LVMI) and carotid atherosclerotic plaques at baseline. A composite cardiovascular endpoint (CEP) consisting of cardiovascular death and nonfatal myocardial infarction and stroke was recorded in national registries. RESULTS: During a median follow-up of 12.8 years, a total of 119 CEPs occurred. In categorical analysis, presence of SOD as well as masked hypertension increased sensitivity of Systemic Coronary Risk Estimation from 73.9 to 89.1% (P < 0.001) and reduced specificity from 60.1 to 41.8% (P < 0.001). In continuous analysis, logUACR [hazard ratio = 1.20 (95% confidence interval [CI] 1.05-1.38), P = 0.009], atherosclerotic plaques [hazard ratio = 1.82 (95% CI 1.21-2.74), P = 0.004] and 24-h SBP [hazard ratio = 1.34 (95% CI 1.12-1.60), P = 0.002] but not logPWV or LVMI predicted CEP in a model with adjustments for age, sex, conventional BP, total cholesterol and smoking. Compared with a risk model using only traditional risk factors, adding PWV, UACR, plaques, LVMI and 24-h SBP increased C-index significantly from 0.76 to 0.79% and produced a net reclassification improvement of 23.3% (P = 0.001). CONCLUSION: UACR and plaques predicted cardiovascular events independently of AMBP and improved risk prediction.